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What Happens During External Radiation Treatment for Lung Cancer

External radiation is the most common type of radiation given for lung cancer. You can get this as an outpatient in a hospital or a clinic. This type of radiation usually comes from a machine called a linear accelerator.

Before you start radiation treatments, you will have an appointment to learn exactly where on your body the radiation beam needs to be directed. The process is called simulation and may take up to two hours. Here’s what you can expect to happen during the simulation process:

You’ll lie still on a table while a radiation therapist uses a machine to define your treatment fields to aim the radiation. The treatment field is also called the treatment volume. It is the exact area in your body where the radiation will be aimed. You may have more than one treatment volume if you have cancer in more than one place. The therapist marks your skin with tiny dots of colored permanent ink or tattoos. The dots are so the radiation will be aimed at the exact same place each time.

You may also have imaging scans, such as CT scans. These help doctors know the exact location of your tumor to better aim the radiation.

You may also have body molds made. These help keep you from moving during the treatment. They also ensure that the treatment reproduces the same way every time.

On the days you have radiation treatment, here’s what you can expect:

You’ll lie on a table while the machine is placed near you. You may have to wear a hospital gown.

The experience is much like that of getting an X-ray, only it lasts longer. It will take about 15 to 30 minutes for the whole process, with about one to two minutes of that actually receiving the radiation.

A radiation therapist may place blocks or special shields to protect parts of your body that don’t need to be exposed to radiation.

The therapist will line up the machine exactly with your marked treatment fields, which were located during the simulation process.

The radiation therapist leaves the room to turn on the machine, but you will be able to talk to the therapist over an intercom.

You can’t feel radiation, but you may hear whirring or clicking noises.

Many treatment plans require that you get radiation treatments every day for five days in a row for several weeks. You will not be radioactive afterward.